Beam-compass.



H. F. OLSON.

BEAM COMPASS.

APPLICATION FILED MAILZB, 1011.

1,001,g33. I Patented Aug. 22, 19111.

um/atom HKOIS on HUGO F. OLSON, OF DORCHESTER, MASSACHUSETTS.

BEAM-COMPASS.

Specification of Letters latent.

Patented Au". 22, 1911.

Application filed March 29, 1911. Serial No. 617,589.

. citizen of the United States, residing at Dorchester, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Beam-Compasses, of which the following is a specification.

This invention relates to improvements in beam-compasses or trammels, and has for its object the provision of an implement consisting of a novel construction or combination of parts, susceptible of the most accurate and delicate adjustment. 1

A further object of the invention is the provision of an instrument comprising a bar or trammel, adjustable points for se-" curing measurements, and means whereby each 'point may be positively secured after the same have been adjusted at predetermined positions.

With the above and other objects in view, this invention consists in the construction, combination, and arrangement of parts, as hereinafter more fully described, claimed, and illustrated in the accompanying drawings, Wherein Figure 1 is a side elevation of the invention; Fig. 2 is a longitudinal sectional view; Fig. 3 is a sectional View on the line 3-3 of Fig. 2; Fig. 4 is a similar view on the line 4-4 of Fig. 2; and Fig. 5 is also a sectional view on the line 55 of Fig. 2.

Throughout the following detail description and on the several figures of the drawings, similar parts are referred to by like reference characters.

Referring more particularly to the drawings, 1 designates a straight bar or trammel, preferably hollow its entire length, having slidably mounted thereon the post 2. The post 2 consists of the enlarged body portion 3 through which the bar 1 passes, and-the upper hollow reduced end 3 which is externally threaded to accommodate the knurled nut 4. It is contemplated that the post 2 may be moved bodily along the bar 1 and, in order to insure various positive adjustments of the former, there is provided the clamping yoke 5 which is inserted over the end 3 of the post by means of an opening in the center thereof, said yoke comprising a plate having its extremities rounded out to conform to the curvature of thebar and bent downwardly so as to rest and bear against. the said bar 1. at opposite sides of the post when the nut 4 is'secured down into engagement therewith, thus clamping the post at the point of desired adjustment. It is desirable that the reduced end 3' should be hollow and there is rovided therein the spiral spring 7 which is adapted to bear against the nut 4 for the purpose of overcoming likelihood of the former becoming loose, as will be apparent. The lower end of the post 2 is internally threaded and terminates in the removable point 8, the upper extremity of which being threaded so as to be secured in position in the post aforesaid. To prevent circumferential movement of the post on the bar 1, there is provided a screw plug Qwhich is screwed into the lower end of the post 2 and which forms a seat for the spiral spring 10 hearing againstthe guide pin 11, which in turn engages in the longitudinal groove 12 extending along the bottom of the bar 1.

From the foregoing, it will be clearliy seen that the post 2 forms one point of a justment of the implement, while the other point is provided by the post 2. The latter consists of the enlarged body portion 3 mounted on the other extremity of the bar 1 in a manner similar to the post 2. In like manner to the post 2 there is provided a clamping yoke 5 and knurled nut 4' screwed upon the reduced end of the body 3. This post has also a spiral spring 7' to hold the knurled end 1 in positive position and the same is seated upon the guide pin 19 adapted to be screwed into the upper reduced portion of the post and to extend into the bar 1 through a longitudinal slot in the same. The said pin 19 bears against the nut 17 in cooperation with the guide pin 18 which is adapted to be screwed into the lower reduced portion of the post 2. and extends into a slot in the bottom portion of the bar 1, bearing against the nut 1'? thus preventing movement of the latter in the bar. The post 2 is provided with a point 8 which is secured into the bottom thereof similarly to that of thepoint 8 in the post 2. To provide means for delicate adjustment of the implement, there is provided the micrometer screw 13 which is screwed into the nut 17 and has integral therewith at its outer extremity the handle or knurled nut 14. Bearing against the said latter in proper position in the bar 1. At theinner extremity of the micrometer screw 13 is provided the bearing plug 20 held in position from movement in the bar 1 by means of the screw 21.

In the use of the invention thus described,

it will be apparent that the post 2 provides a point for all general adjustments and the same may be moved bodily throughout the greater portion of the bar 1 and is adapted to be clamped in the desired position by means of the yoke 5 against which the nut 4 may be screwed. The opposite point of adjustment to determine the desired length of measurement is secured by manipulation of the post 2'- and it will be apparent to one familiar with the uses of an implement of this character that, by means of rotation of the handle 14 which through the means of the screw 13 threaded into the nut 17 will advance the post 2 very accuratelyeven to one thousandth of an inch. It will furpencil point and, with the post 2 as a centermg point, the operator may describe any de sired circles. It is contemplated also that the groove 12 and the openings through which the guide pins 18 and 19 extend shall be in alinement and hence the posts are prevented from circumferential movement thereby.

Having thus described my invention, what is claimed as new is 1. In a beam-compass, the combination 0 ether or trammel, a post mounted thereon, and means for holding said post at predetermined adjustments in the length of the bar consisting of a yoke detachably carried by said post and having spaced portions at opposite sides" of the post arranged to directly engage the bar, and an adjusting. nut

on the 'post engageable with the yoke for effecting clamping cooperation with the bar.

2. In a beam-compass, the combination of a bar or traminel, a post having an opening therethrough receiving said bar and perand formed with spaced parts extending v laterally into engagement with the bar, an an adjusting nut screwed upon the end of the post adjacent the yoke and co-acting with the latter to hold the same in clamping cooperation with the bar, the post having a point at its opposite end.

3. In a beam compass, the combination of a hollow bar, a micrometer screw arranged in 'said bar, bearing blocks in which the opposite ends of said screw are mounted and also received and housed within the bar, fastenings for preventing the turning of said blocks, a handle connected with one end of said screw for turning the same, a post having an opening .therethrough receivingthe bar, a nut on the micrometer screw, and a member passing throughthe bar into interlocking connection with the nut aforesaid.

4. In a beam-compass, the combination of a hollow bar, a micrometer screw arranged in said bar, bearing blocks in which the opposite ends of said screw are mounted and extended. through the slots of the bar into interlocking engagement with the nut on the micrometer screw.

5. In a beam-compass, the combination of a bar or trammel, a post mounted thereon, means for moving said post longitudinally .on the bar comprising a micrometer screw,

hearings in the bar for the ends of said screw, and a fastening for one of said bearings movable into and out of interlocking connection with the micrometer screw.

In testimony whereof I aflix my signature in presence of two witnesses.

HUGO F. OLSON.

Witnesses:

JOHN EDISON, FRANK SUNDIN. 

